Promising rice genotypes with enhanced root growth and HMA transporter gene expression under zinc deficient conditions

Zinc (Zn) is an essential micronutrient involved in biochemical processes for growth and development of plants. Here, we investigated the variability in response of 15 rice genotypes for number of roots, shoot and root length, metal tolerance score under zinc sufficient (ZS) and zinc deficient (ZD) conditions using hydroponics system. Significant variation was observed among genotypes for four traits under ZS and ZD conditions. Five genotypes were identified with promising performance under ZD, which could be deployed in rice breeding program for zinc deficiency. Expression analysis of OsHMA2 and OsHMA3 in root tissues of five selected zinc efficient genotypes has shown up-regulation of OsHMA3 in three genotypes with high grain zinc. Root length was highly correlated with OsHMA2 and OsHMA3 under ZD condition.